Rotating Electroosmotic Flow Of Third Grade Fluids Between Two Microparallel Plates

Microfluidics is one of the most important research areas in micro-electro-mechanical system (MEMS). One way to transport fluids through microchannel in these miniaturized devices without mechanical moving part is to utilize electroosmosis (EO) driven by applied voltages. Nowadays, the electroosmosis flow driven is widely used in medicine, chemical engineering and biology fields due to its ease of control and high efficiency.This study is devoted to concerning the rotating electro-osmotic flow (EOF) of an incompressible third grade fluid between micro-parallel plates, which is under the system of applied electric field. The Cauchy momentum equation will be modified by substituting the constitutive relation of third grade fluid and electric field into the Cauchy momentum equation. For the linearized to Poisson-Boltzmann (P-B) equation electrical potential satisfied, the exact solutions of the electric potential distribution are given. The approximate analytical solutions of the velocity profile and the volume flow rate are achieved by using perturbation method under the assumption of small non-Newtonian parameter A. In addition, the finite difference method is used to obtain the numerical solutions. We compare the analytical solutions with the numerical solutions within admissible parameter range, and obtain a good agreement between these solutions. The influence of the Reynolds number Re, the dimensionless non-Newtonian parameter A, the dimensionless electro-kinetic width K on the rotating EOF velocity profiles and volume flow rate are investigated in detail. With the increasing Reynolds number Re and non-Newtonian parameter A, the velocity is decreasing. The large angular velocity has an obvious effect near the center core of the micro-channel and causes a reversal in the velocity direction.